中文摘要：

通过对不同大气CO2浓度水平下的小麦观测试验，研究了大气CO2增加对小麦旗叶衰老过程中丙二醛、光合色素、净光合速率的影响以及产量构成的变化。结果表明，在大气CO2含量为550和750μmol／mol时，与大气CO2背景浓度相比，小麦灌浆过程中旗叶MDA含量分别下降了6．4％～15．0％和14．1％～18．9％，叶绿素含量则平均增加11．6％和16．7％，类胡萝卜素含量也同步增加10．1％和16．9％，同时高浓度CO2促进了净光合速率的提高，平均提高幅度分别为14．9％和22．1％，明显延缓了旗叶衰老进程。CO2含量增加提高了小麦小穗数、穗粒数和千粒重，产量分别增加13．3％和21．7％。

英文摘要：

The content of malondialdehyde （MDA）, chlorophyll, carotennoid, net photosynthetic rate （Pn） in wheat flag leaf and yield components of wheat were measured, and their responses to the increase of CO2 were analysed. The results showed that the content of MDA decreased by 6.4% -15.0% and 14.1% -18.9% respectively at filling stage under elevated （550 and 750 μmol/mol） CO2, compared to the ambient air CO2 concentration. At the same time, the average contents of chlorophyll and carotennoid increased by 11.6% - 16.7% and 10.1% - 16.9%. It was also found that the average Pn increased by 14.9% and 22. 1% at filling stage. The senescence of flag leaf was significantly postponed at high CO2 conditions. The grain yield of wheat increased by 13.3% and 21.7% in two high CO2 levels.